The story of Square Enix's production difficulties and mismanagement of talent goes back to the time of the merger, and is a result of being unable to shed their 90s-era development practices deeply embedded in their culture. They've got more problems than just being unable to get a flagship product out the door, if you can believe that. A Realm Reborn managed to fix their cash flow problems, which I suppose is rightly their first priority, but it did so at the cost of significantly disrupting their operations throughout the company, by siphoning young talent that they need to be nurturing with smaller projects instead.

However, the only individual who can conceivably be blamed for all this is Yoichi Wada, who already has been.